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Polydopamine (PD) is a synthetic melanin analogue of growing importance in the field of biomedicine, especially with respect to cancer research, due, in part, to its biocompatibility. But little is known about the cytotoxic effects of PD on cancer cell lines. PD is a UV-vis absorbing material whose absorbance overlaps with that of formazan salts, which are used to assess cell viability in MTT assays. In this study, a protocol has been established to eliminate the contributing absorbance of PD at 550 nm, and has been applied to characterize the cytotoxicity of PD nanoparticles in both healthy and breast cancer cell lines. Once the protocol is applied, it was found that PD is per se an antineoplastic system, meaning it selectively kills cancer cells, especially those of breast cancer, but it has no toxic effect on healthy cells. The mechanism of action could be related to the production of ROS and the alteration of iron homeostasis in lysosomes. To the best of our knowledge there are only a few examples of nanoparticle systems devoid of drugs that selectively kill cancer cells.

Polydopamine (PD) is a synthetic melanin analogue of growing importance in the field of biomedicine, especially with respect to cancer research, due, in part, to its biocompatibility.  相似文献   
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Vega E  Rudolph MI 《Endocrine》2002,18(2):167-172
Oxytocin (OT) inhibits the uptake of serotonin (5HT) into uterine mast cells. This may modulate 5HT bioavailability in the myometrium. Because 5HT is an important endogenous uterotonic compound, it has been postulated that this effect of OT may contribute to its potency as a labor inducer. This also predicts the presence of oxytocin receptors (OTRs) and transducing signals that will interact with 5HT transporters (SERT) in mast cells. In this study, OTR and SERT were characterized in murine peritoneal mast cells by radioligandbinding studies. Saturation assays for OTR showed no changes in K d along the estrous cycle (6.95±2.76 nM in estrus and 4.07±1.73 nM in diestrus) but an increase in B max in estrus (0.71±0.08 pmol/106 cells and 0.37±0.05 pmol/106 cells in estrus and diestrus, respectively). B max and K d for SERT were not affected along the estrous cycle. The signaling between the OTR and the SERT was analyzed by measuring the extent of inhibition of OT and PMA (activator of protein kinase C on 5HT uptake and the capability of Ro318220 (specific inhibitor of PKC) to increase 5HT uptake and block the effect of the above compounds in mast cells. The results showed that in murine peritoneal mast cells in vitro (1) ovarian hormones modulate OTR but not SERT expression, (2) the magnitude of OT action on 5HT uptake depends on the number of OTRs expressed in mast cells, and (3) the signaling between OTR and the SERT is mediated through the activation of protein kinase C. It is concluded that the ovarian hormones have a modulatory action on 5HT uptake which involves OT-mediated mechanism.  相似文献   
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BACKGROUND AND OBJECTIVES: Cardiac resynchronization via left ventricular or biventricular pacing is an option for selected patients with ventricular systolic dysfunction and widened QRS complex. Stimulation through a coronary vein is the technique of choice for left ventricular pacing, but this approach results in a failure rate of approximately 8%. We describe our initial experience with minimally invasive surgical implantation of left ventricular epicardial leads using video-assisted thoracoscopy. PATIENTS AND METHOD: A total of 14 patients with congestive heart failure, NYHA functional class 3.2 (0.6) and mean ejection fraction 22.9 (6.8)% were included in this study. Left bundle branch block, QRS complex >140 ms and abnormal septal motion were observed in all cases. Epicardial leads were implanted on the left ventricular free wall under general anesthesia using video-assisted thoracoscopic surgery. RESULTS: Lead implantation was successful in 13 patients. Conversion to a small thoracotomy was necessary in one patient. All patients were extubated in the operating room. None of the patients died during their hospital stay. Follow-up showed reversal of ventricular asynchrony and significant improvement in ejection fraction and functional class. CONCLUSIONS: Minimally invasive surgery for ventricular resynchronization using video-assisted thoracoscopy in selected patients is a safe procedure that makes it possible to choose the best site for lead implantation and provides adequate short- and medium-term stimulation.  相似文献   
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Background and objective

Online haemodiafiltration (OL-HDF) with high convective transport volumes improves patient survival in haemodialysis. Limiting the amount of convective volume has been proposed in patients with diabetes mellitus due to glucose load that is administered with replacement fluid. The objective of the study was to analyse the influence of substitution volume on the evolution of the metabolic profile and body composition of incident diabetic patients on OL-HDF.

Material and methods

Prospective observational study in 29 incident diabetic patients on postdilution OL-HDF. Baseline data included clinical and demographic data, laboratory parameters (metabolic, nutritional and inflammatory profile) and body composition with bioimpedance spectroscopy (BIS). Laboratory parameters and mean substitution volume per session were collected every 4 months, and in 23 patients a further BIS was performed after a minimum of one year. Variations in glycosylated haemoglobin (HbA1c), triglycerides, total cholesterol, LDL-c, HDL-c, albumin, prealbumin and C reactive protein (CRP) were calculated at one year, 2 years, 3 years, and at the end of follow-up. Quarterly and annual variations were calculated as independent periods, and changes in body composition were analysed.

Results

Age at baseline was 69.7 ± 13.6 years, 62.1% were male, 72.3 ± 13.9 kg, 1.78 ± 0.16 m2, with 48 (35.5-76) months on dialysis. Approximately 81.5% received insulin, 7.4% antidiabetic drugs and 51.9% statins. Mean substitution volume was 26.9 ± 2.9 L/session and follow-up period (time on OL-HDF) was 40.4 ± 26 months.A significant correlation was observed between mean substitution volume and the increase in HDL-c (r = 0.385, p = 0.039) and prealbumin levels (r = 0.404, p = 0.003) throughout follow-up. Moreover, substitution volume was correlated with a reduction in CRP levels at one year (r = –0.531, p = 0.005), 2 years (r = –0.463, p = 0.046), and at the end of follow-up (r = –0.498, p = 0.007). Patients with mean substitution volume > 26.9 L/session had a higher reduction in triglycerides and CRP, and an increase in HDL-c levels. These patients with > 26.9 L/session finished the study with higher HDL-c (48.1 ± 9.4 mg/dL vs. 41.2 ± 11.6 mg/dL, p = 0.025) and lower CRP levels (0.21 [0.1-2.22] mg/dL vs. 1.01 [0.15-6.96] mg/dL, p = 0.001), with no differences at baseline.Quarterly comparisons between substitution volume and laboratory changes [n = 271] showed a significant correlation with a reduction in HbA1c (r = –0.146, p = 0.021). Similar findings were obtained with annual comparisons [n = 72] (r = –0.237, p = 0.045). An annual mean substitution volume over 26.6 L/session (29.3 ± 1.7 L/session vs. 23.9 ± 1.9 L/session) was associated with a reduction in HbA1c (–0.51 ± 1.24% vs. 0.01 ± 0.88%, p = 0.043). No correlation was observed between substitution volume and changes in weight, body mass index or BIS parameters.

Conclusion

There is not enough evidence to restrict convective transport in diabetic patients on OL-HDF due to the glucose content of the replacement fluid.  相似文献   
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Clinical Rheumatology - Discordance (misalignment) regarding treatment satisfaction may exist in real-life clinical practice between patients and their physicians. We aimed to assess physician and...  相似文献   
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